1. Field of the Invention
The present invention relates to a system for melt-sealing glass ampoules with a microorganism containing sample housed therein at a desired temperature and in an atmosphere under a desired degree of evacuation in such a state that the sample has a moisture content thereof lowered.
2. Discussion of Background
Glass ampoules have been used as containers for storing a sample, which contain a microorganism to be utilized for various kinds of tests, researches and other purposes.
For the purpose of sealing that sort of sample in an ampoule, there has been a method wherein the ampoule is immersed in a bath with liquid nitrogen or the like filled therein to be stored in a frozen state. However, it is difficult to reduce the installation costs and the running costs of the storing equipment in this method.
From this viewpoint, there has been used a method wherein that sort of sample is stored by melt-sealing an ampoule with the sample therein while evacuating the ampoule to decrease the moisture content of the sample.
However, it has been not easy to carry out the evacuation treatment for each ampoule.
Additionally, the sealing operation for that sort of ampoules has been carried out by heating and melting an upper open portion of each ampoule by use of a burner or the like with the ampoule being evacuated as stated earlier. It is not easy to carry out this sealing operation.
The evacuation treatment creates a drop in the boiling point of the sample housed in an ampoule. In order to cope with this problem, it is necessary to decrease the temperature of the ampoule, depending on the degree of evacuation, until the moisture content of the sample housed in the ampoule has reached a desired moisture content. However, it has been unavoidable to carry out the evacuation treatment with the sample being frozen at a temperature lower than needed, since the temperature of the sample housed in the ampoule is gradually increasing until the moisture content of the sample housed in the ampoule has reached the desired moisture content. Normally, that sort of samples have been frozen at as low a temperature as minus 80 degrees Celsius.
There has been also a treatment wherein the moisture content is decreased by gradually increasing the degree of evacuation in the ampoule without freezing the sample (so-called “L-dry”). However, it has not been possible to completely deny the possibility that the microorganism contained in the sample could be adversely affected by temperature changes until the treatment has been completed, since there have been no specific measures to keep the temperature of the ampoule constant until completion of the treatment.